The goal of this training program is to educate scientists who will contribute to the fight to prevent birth defects (congenital malformations and neurobehavioral abnormalities). The approach taken is to view birth defects as molecular perturbations of developmental pathways. Graduate students supported by this grant in the Molecular and Developmental Biology (MDB) Graduate Program take classes in developmental biology, embryology, molecular genetics, biochemistry, cell biology, and teratology and for some also in neuroscience and biostatistics. The molecular focus is carried throughout the program, including seminar and journal clubs, and in laboratory experiences. All laboratories in the program use molecular techniques and many also use cellular and systems methodologies. Trainees from this program have been very successful, moving on to academic, industry and government research positions in developmental toxicology, teratology, and/or developmental neurotoxicology. There is a national shortage of scientists trained in these areas and demand for our graduates remains strong. Our graduates have proven to be well prepared causing employers to return to the investigators for more of their trainees. Accordingly, request is made to train four pre-doctoral students and three postdoctoral fellows. This is the same number of pre-doctoral positions and an increase of one postdoctoral position compared to the last five years. The request for three postdoctoral positions is the same as was funded during the preceding cycle (10 to 5 years ago) and the same as was approved for funding 5 years ago. Since that time demand for scientists trained in these areas has increased and the number of applicants for the postdoctoral positions has also increased. In response, the investigators have expanded the training faculty and seek reinstatement to the prior level of three postdoctoral positions. The duration of training for postdoctoral fellows is three years and for graduate students, five years. It should be noted that recent changes to the MDB curriculum have the potential to reduce the time to earn the Ph.D. degree to 4.5 years. In addition, the contexts in which this training grant operate, i.e., the MDB program and the Children?s Hospital Research Foundation, are undergoing major expansions that bode well for even greater future success of this training grant in the next five years.